Introducing "Dirty Penny" - Former $2010[$2012] GRM Project, Running. Driving. Boosting. FUN! Options

[jpnovak]

The car runs well around the neighborhood. Still need legal tags to venture farther away. These are in the works. At least insurance is current.

[jpnovak]

I am finally starting to tune the EFI system. What fun this is. Drive around until you reach a point where the car runs like crap, look at the AFR and realize its too lean, start adding fuel and feel the car gain torque. Keep adding fuel until you have a stable AFR and feel the car really want more throttle and is happy. Rinse, Repeat.

Then go back at look at the fuel map and realize that you are dumping crazy amounts of fuel when the car comes into boost. Some would say, nothing good can come from this much fuel requirement. Some might say that the car is making considerably more horsepower in twin turbo trim that the base map from the single turbo trim. Otherwise there is no explanation for requiring that much more fuel.

And I only have the car limited to about 8psi right now. Wait till I get to 18!

Yes, it is my current mid-engine rocket ship.

[DBCooper]

All I have to say about that is

(IMG:http://www.914world.com/bbs2/uploads_offsite/i379.photobucket.com-2618-1363639289.1.jpg)

Car gets to be a LOT of fun when that boost comes in, doesn't it? You totally stop trying to drive subtle. Lee. Aim and shoot, hold on, repeat. It's serious fun, and mine isn't even as strong as yours.



.

[jpnovak]

Yes, I will use VEAL. However, I start with datalogs and roughing in the map by hand. This allows me to have VEAL make minor adjustments where it works best. I have found that if the map is way off VEAL is difficult to control. If you give it more authority to make changes it will start to change where you don't want it to.

The best method is to have someone else drive while I tune. Much faster process. But, I don't have a passenger seat and that makes it difficult right now. But if that is the worst of my problems from here on out I will be fine.

[RonW]

bump for an update

[jpnovak]

Hey Ron,

Let's see...

I managed to get a new driver's seat installed. I picked up a GT3 fixed back replica seat a few months ago for $99 on ebay. Carbon fiber goodness but the stock seat is still lighter. This one offers significantly more support.

Otherwise, I am still tuning the car but I do not have a lot of time to devote to it. I really need large blocks of time (1.5 hours) of driving but the schedule has not allowed.

When tuning I ran out of VE table space (max 255) and had to rescale the table by increasing the req_fuel value and scaling the VE table down the same percentage. I should now have enough room to dump more fuel under boost. Of course, this has slightly messed up my midrange. Its just not as smooth as it could be.

I continue to work on it.

[jpnovak]

So, Its been a few weeks since I updated the thread.

1. two weeks ago I had a CV joint come apart while tuning. The inner subaru came apart when the retaining clip came off. No damage but I had to wait for some parts. In the end, the axle on the DS was 3/8" too short and that was the root cause. I had to fabricate a new axle and get it installed. That was completed last night and the car is driving again.

2. tuning. The car is running well at most of the NA sites. I am now ready to start creeping into boost. I am taking my time since I don't want to blow this up while driving.

3. I completely revamped the braking system to stock. I refinished the rotors and installed some Ferodo DS2500 pads. These are a long time favorite dual purpose street/track pad that are cheap compared to others. What a difference. The car stops appropriately now.

4. Suspension... During the tuning process I have blown out both front shocks. Now you know what happens when you let your car sit untouched for 9 years. The seals will go and fluid will spill. Let's just say that the car will bottom out on every small bump now. Yeah, they are that bad. Digging through my stash to see if there are some old inserts laying around.

5. Track time... I had signed up for an open track day tomorrow (May 18). The car is not ready since its not tuned and the front shocks are blown. So I will take the bimmer DD instead and have some fun. Next time I am taking Penny.

6. Finally got my lost title replaced. Should have it registered next week and can finally start a real tuning process.

I promise to post video once the car is running properly.

[jpnovak]

Let's see where are we with this project. I finally connected with the PO and got the title signed over. It took longer than expected to get the replacement for the lost title.

Penny is now legal for driving. To celebrate I took her out on a nice drive this morning to meet some friends for breakfast. Its funny driving a fully stickered up car around town. Lots of waves and thumbs up. Also lots of drivers that ignore everything around them. Yes, its the usual.

Anyway... I finally managed to get the cooling system working. I stay right around 195 even in the triple digit TX heat. I have fought corrosion in the motor, air bubbles, and a few other problems. What finally worked? 20% antifreeze, a bottle of water wetter and the rest distilled water. Burp well. Bleed well and then allow the system to work. The biggest improvement was the etching flush I made with oxalic acid to get rid of the old scale and rust. The owner of this engine must have let water sit in the system. Lots of yucky crud came out during the flush. Glad that's over.

The engine is tuned nicely. Currently running 12psi boost. The car is really quick as it is. I will still work through tuning to 18psi as I get time.

Now my problem is fuel delivery. The new Bosch fuel pump I installed a few months ago just took a dump. I was wondering why the car kept going lean above 3K. Turns out it just can not deliver enough fuel. Tomorrow morning I will get a new one and have that fixed. Only takes a few minutes to swap them out. I think it takes longer to remove the access panel and unbolt the pump compared to swapping lines on it.

After the new pump is installed I will get some video up and take some new pictures. I am just glad to be able to drive outside my neighborhood.

[RonW]

congrats jamie, looking forward to seeing / hearing Penny making a few runs

[jpnovak]

I managed to grab a few videos today. The car is running well now. I am currently at 13psi. Time to start turning up the boost. Though I am not sure how much more these small turbos can crank out.

http://contour.com/stories/file0033--498

http://contour.com/stories/porsche-914-subaru-ej20tt-swap

[RonW]

jamie,
hows the car tuning coming along? you gonna make the 2013 challenge next month? hoping so!

[jpnovak]

Hey Ron,

No, I am not going to FL for the event. Current work status (and thus financial concerns) have me in a cash conservation mode.

Penny is running and driving great. Registered, legal and lots of fun. In fact, She has been my DD for a few weeks now. Although, I am not quite ready to give up the usual DD.

So, I don't know what will happen to her. I will probably hit a few track events this spring and then she may have to be sold so that I can move on to my next project. I am almost ready for something new.

The one thing I do not like is the TT setup. The turbos spool late and I do not get full boost until after 3500 rpm. The car pulls well to redline (currently 7K) though I am maxing out my injectors under full boost. They exceed their duty cycle and dump fuel by basically staying open. Its not a problem of going lean, Quite the opposite. The car quickly goes rich due to lack of fuel metering control.

Another problem I have had is IC temps. Of course, the car has been in TX and up until last week we have still been in the 90s. I have not driven in the recent cold front and rain to see if this is all under control. I am concerned that the engine bay is siphoning cold air from below, heating it across the engine/exhaust and then pushing hot air across the IC at the top. Remember, the downward airflow in a stock 914 is due to the engine cooling fan - something I am missing. (IMG:style_emoticons/default/smile.gif)

I may have to reconfigure the IC to get really low charge temps.

So, If anyone is reading and interested please let me know.

[RonW]

Jamie,
sorry to hear about the work status! that really bites. i'll keep my fingers crossed for a speedy resolution to that.

i agree with you on both issues and unfortunately, i think it will take bigger injectors (what size are they currently?) and switching to a water air IC system and remotely mounting the IC radiator (or ice box reservoir it that is sufficient volume.)

hope to see more of the car in action vs selling it for next project but if the next project is another suby conversion, bring it on (IMG:style_emoticons/default/beer3.gif)

[jpnovak]

Ron, Thanks for the suggestion on larger injectors. I thought I would try another route based on parts availability in the garage. I am finally making progress on Penny.

One of the issues I have had with Penny is that the engine would cut out at high rpm under boost.

I have datalogged and looked and looked to find the problem. The AFR holds steady at 11.1 (good target for boost) until about 4900 rpm. Then all of a sudden it starts to go rich. Despite lowering the fuel value in that area of the map it still goes rich. I finally realized that the injectors were maxing out on the duty cycle. Effectively, the electrical signal is trying to switch on/off faster than the injectors are physically capable of handling. This means they basically stay open and then dump fuel. Too much fuel drops AFR below 10 which causes a rich misfire.

So last night it was time to fix the problem. I did not have larger injectors. But I can make more fuel flow through each cycle by raising fuel pressure. I took a stock Subaru fuel pressure regulator (FPR) and cut the end off. This meant I could pull the regulator portion out. I welded a cap onto the end. I should have taken a picture.

Having bypassed the stock regulator I installed the FPR from the ST. Its adjustable. I raised the pressure from stock 32 to 44. then adjusted the fuel scaling factors and the engine was running well. Basically, I had to lean it out because I was flowing more fuel. on the way to work it would pull to 6K without any issues. It still goes rich but that is a result of tuning, not duty cycle limits. At 6200 and 16psi I was just below 90% duty cycle. The stock injectors did not start having problems until about 95% duty cycle in my previous datalogs. Cool! Now I just need to fine tune the EFI again.

Honestly, she runs even better. I suspect higher fuel pressure is giving slightly better atomization of fuel.

WooHoo!. Oh, and cold weather is good for boost.

Another note. If the stock 420CC injectors are maxing out this should occur at a calculated 270 FWHP. HMM. If I have exceeded that limit I wonder where I am now. How about a little math.

From my calculations increasing the fuel pressure changes should add 6.8% fuel flow. Converting this to HP puts me just over 300. Of course, I am also loosing volumetric efficiency (BSFC). So somewhere close to this is fine with me. The car feels really quick above 4K rpm now.

I will report back after some more tuning.

[jpnovak]

Penny just keeps getting better. As I finalize the engine tune she is much easier to drive and more responsive. The tach swings very quickly from 4-7K. Yeah!

I did find out that she does not like sitting in traffic. Temperatures begin to climb without airflow. (IMG:style_emoticons/default/sad.gif)

Doesn't matter, she is still my daily driver for a while until I sort everything out.

[RonW]

great to hear you were able to incr fp and get a little more out of the injectors! im surprised the stock fp was only 32 psi, i though for sure it would have been in the 40's. i dumped my stock fpr as well and run an aeromotive that was already in my engine bay from the prior ms/t4. i don't recall any change in my tune though going from the stock to the aeromotive which is set at 43psi.
i'll have to look back thru your thread to see how your venting, i think it was to the side in to the wheel wells but maybe you should go thru the hood.

[jpnovak]

Ron,

I am venting through the hood. I just don't have a fan. Without it the car does not have any airflow. Maybe I need one. The radiator is relatively small for a car without a fan. When moving the car stays nice and cool.

Yes, the factory spec for fuel pressure is relatively low. It is a rising rate regulator. Its just that the initial rates are not good enough considering I am running both turbos wide open into an open exhaust.

[veekry9]

All I have to say about that is

(IMG:http://www.914world.com/bbs2/uploads_offsite/i379.photobucket.com-2618-1363639289.1.jpg)

Car gets to be a LOT of fun when that boost comes in, doesn't it? You totally stop trying to drive subtle. Lee. Aim and shoot, hold on, repeat. It's serious fun, and mine isn't even as strong as yours.



.

Made Me Laugh

OldSchool courtesy of Playboy Mag.

[jpnovak]

There has got to be a story or caption to that picture...

I am finally changing the title. I am now calling it a former GRM Challenge car. Its time to put a little money into this car to really enjoy it. I have been working on suspension and now need some new injectors. This will probably put me over budget. This is not a problem for this year as I am not able to go to the event. Maybe next year. Until then there are quite a few track days to complete.

Current Development Update:

Over the past two weeks I have been studying and configuring the vacuum lines on Penny. Originally, I left most of the factory connections in place. Maybe that was not the best idea.

It all started with the swap of the BOV and wastegate connections. They were connected with the BOV above the throttle and wastegates below. This was opposite of the way it should be. This is mostly my fault when I swapped the wiring harness and disconnected everything. After that, the car ran much better.

I had added a manual boost controller and yet, the car still would not pull more than 10psi. I found out that this is the factory spring setting on the wastegates. After some digging I found that the DS turbo had a vacuum bypass that connected the pressure side to the WG. HMM. This meant that my boost controller was bypassed. No wonder it would not hold boost.

AFter swapping and plugging a few vacuumports on the turbo I can now easily get 16psi. This is a whole different level of high rpm fun. Oh Yeah! Now I can finalize the tune and set an appropriate boost level.

the downside is that my injectors are way too small. I will be replacing those in the next week or so. Time to go spend a little money.

[rhodyguy]

will you have to upsize on the fuel pump too?